SSM2141
MAINTAINING COMMON-MODE REJECTION
Figure 5. Suitable Instrumentation Amplifier
Requirements can be Addressed by Using an
Input Stage Consisting of A
1
, A
2
, R
1
and R
2
OUTLINE DIMENSIONS
Dimensions shown in inches and (mm).
Figure 1. Precision Difference Amplifier. Rejects
[E
1
+
E
2
]
Common-Mode Signal =
by 100 dB
2
8-Pin
Epoxy Mini-DIP
P-Suffix (N-8)
0.430 (10.92)
0.348 (8.84)
8
5
0.280 (7.11)
0.240 (6.10)
1
4
PIN 1
0.210 (5.33)
MAX
0.160 (4.06)
0.115 (2.93)
0.060 (1.52)
0.015 (0.38)
0.130
(3.30)
MIN
SEATING
PLANE
0.325 (8.25)
0.300 (7.62)
0.195 (4.95)
0.115 (2.93)
Figure 2. Precision Unity Gain Inverting Amplifier
0.022 (0.558) 0.100 0.070 (1.77)
0.014 (0.356) (2.54) 0.045 (1.15)
BSC
0.015 (0.381)
0.008 (0.204)
8-Pin Narrow Body SO
S-Suffix (SO-8)
0.1968 (5.00)
0.1890 (4.80)
Figure 3. Precision Summing Amplifier
0.1574 (4.00)
0.1497 (3.80)
8
1
5
4
0.2440 (6.20)
0.2284 (5.80)
PIN 1
0.0098 (0.25)
0.0040 (0.10)
0.0688 (1.75)
0.0532 (1.35)
0.0196 (0.50)
x 45°
0.0099 (0.25)
0.0500 0.0192 (0.49)
SEATING (1.27)
PLANE BSC 0.0138 (0.35)
0.0098 (0.25)
0.0075 (0.19)
8°
0°
0.0500 (1.27)
0.0160 (0.41)
Figure 4. Precision Summing Amplifier with Gain
–6–
REV. B
PRINTED IN U.S.A.
C1532–2.5–5/91
In order to achieve the full common-mode rejection capability
of the SSM2141, the source impedance must be carefully
controlled. Slight imbalances of the source resistance will result
in a degradation of DC CMR—even a 5
Ω
imbalance will
degrade CMR by 20 dB. Also, the matching of the reactive
source impedance must be matched in order to preserve the
CMRR over frequency.
AD [ ANALOG DEVICES ]
